Sight device for machine guns



June 12, 1934. w Q HAUBROE 1,962,590

SIGHT DEVICE FOR MACHINE GUNS Filed July 51, 1931 3 Sheets-Sheet l Wavy r V rsslmgmgggmmm mswumemrs Maura? M3 June 12, 1934. w. c. L. HAUBROE 1,962,590

SIGHT DEVICE FOR MACHINE GUNS Filed July 51, 1951 4 3 Sheets-Sheet 2 p I Fig.5- I I 2 1,, 32 6 36a. 35 2; H 32 W //Vl/E/VT07T MI. 6. L HHUBROE M E m s T R UJMIENTS v l 1 V V H V 7 7 June 12, 1934.

W. C. L. HAUBROE SIGHT DEVICE FOR MACHINE GUNS Filed July 31, 1931 3 Sheets-Sheet 3 Fig.9. 4 T/ T \T W\Y IW Patented June 12, 1934 SIGHT DEVICE FOR MACHINE GUNS Werner Christian Lassen Haubroe, Copenhagen, Denmark Application July 31, 1931, Serial No. 554,236 In Denmark August 18, 1930 4 Claims.

The invention relates to a sight device for machine guns and the like for use against movable targets in the air, especially air craft.

As is well known, the elevation of the gun above the sight line corresponding to firing over a certain range decreases with increasing angular height of the target. The invention has for its object to provide an arrangement by means of which the correction of elevation corresponding to the varying angular height of the target is effected automatically. This is effected by the sight devices being supported by a common frame, one frame member of which is formed by a shaft connected partly to a device for adjusting the sight devices according to the directiongp motion of the target and the position of this direction relatively-to a horizontal line, and partly to a frame attached to the machine gun, the connection between this frame and the first mentioned frame being formed by a carriage, which by means of a draw-bar is connected to a device for adjusting the sight devices according to the height of the target in the air. The invention comprises further the detailed construction of the sight device and the various parts of the same.

Two different constructions of such a sight device are illustrated on the drawings, where Fig. 1 is a perspective outline view illustrating a sight device embodying the features of the present invention, showing the same attached to a machine gun, the broken lines indicating the position of the line of sight and the axis of the gun bore relatively to the target and the point hit;

Fig. 1a is a detail side view of a portion of the sight operating mechanism, certain of the parts being shown in different positions in full and dotted lines respectively;

Figs. 2 and 3 are respectively a side view and a plan View of the sight device;

Figs. 4 and 5 are respectively an end view and a vertical central section of the front part of the sight device;

Fig. 6 is a detail side view, broken away, of the rear part of the sight device;

Fig. 7 is a Vertical sectional view taken approximately on the line VIIVII of Fig. 6;

Fig. 8 is a side view of a modified form of the sight device, showing the same attached to a gun support; and

Fig. 9 is a plan View of the device shown in Fig. 8.

Referring to the drawings, 1 is a machine gun and 2 the support of the same, in which the machine gun is supported by horizontal trunnions 3,

so that it is free to swing in a vertical plane, while the support itself is pivoted about a vertical axis. To one of the trunnions 3 a supporting bracket 4 is attached, which is firmly connected to the support 2, in such a manner that the position of the supporting bracket relatively to the support and to the axis of the trunnion 3 will remain unaltered. The supporting bracket is fitted, at its free end, with a bearing 5 for a vertical spindle 6 the axis of which is situated in the vertical plane passing through the trunnions 3, and the bottom end of which supports a handle '7, while the top end supports a casing 8 connected to a sleeve 9, see Figs. 6 and 7, on the spindle. Axially in the casing a screw 10 is journaled which is adapted to rotate but not to slide in the casing, and which supports a nut 11 adapted to slide and to be guided in the casing and being fitted with a lug 12 projecting up through a longitudinal slot in the top of said casing. The screw 19 is fitted at one end with a head 13 by means of which it can be rotated. Along one edge of the longitudinal slot there is provided a scale 14, see Fig. 6. Below the scale the outer wall of the casing 8 is fitted with a toothed segment 15, the teeth of which serve as check-teeth for a spring actuated check-pin 16 provided in the sleeve 9 on the top end of the shaft 6. The lug 12 on the nut forms one part of a universal joint 12, 17, Fig. l, the other part 17 of which is attached to the rear end of a spindle 18 forming one frame member of a rectangular frame 18, 19 the rear end frame member 19a of which supports an arm 20 pointing upward and supporting, at its free end, a circular plate 21 in the center of which there is a hole 22 forming the rear sight member. At its front end the frame 18, 19 supports a casing 23, the bottom part of which contains a gear wheel 23a, Fig. 4, attached to the spindle 18 and engaging a pinion 231), which is similarly journaled in the casing and is situated above the gear wheel. This pinion engages an external row of teeth 23c on a circular ring 24 rotatably disposed in an annular frame 24a on the casing 23. In the ring 24 a wire cross is provided, one wire 25 of which is double, so that a space 27 is formed between the two parts thereof. The other wire 26 of the wire cross is single and :is discontinued across the space 27 between the wires 25, Figs. 4 and 5, and supports two arrows 28 and 29, which are parallel to the space 27 and both point to the same side. The point at which the wire 26 would intersect the space 27 if carried across said space forms the front sight.

On that one of the gun trunnions 3 that faces towards the side where the sight device is disposed, normally on the right-hand side of the gun, a sleeve 30 is provided which is pivoted about the trunnion 3, and to which one end frame member 31 of a rectangular frame 31, 32, 33 and 34 is attached. The other end frame member 33 of this frame is attached to the machine gun 1 by means of a rod 35, in such a manner that the frame follows the rotation of the gun in the vertical plane. On each of the longitudinal frame members 32 and 34 of the frame a sleeve 36, (Figs. 1, 2 and 3) is provided, which sleeves are interconnected by a rod 36a. On the spindle 18 a sleeve 38 is provided, to which sleeve is attached a fork 370. which is swivelled on the end of a rod 37 rigidly connected to the rod 36a. The sleeves 36 and 38 form in combination with the rods 36a and 37 a sliding member or carriage which is adapted to slide forward and backward on the two rectangular frames 31, 32, 33, 34 and 18, 19. Between the rod 37 and a one-armed lever 40 a pull-bar 39 is provided, which is pivoted to the said two parts. One end of the lever 40 is pivoted about a pin 41 on a plate 42, which is rigidly connected to the supporting bracket 4. This plate is fitted with a curved edge 43, the centre of which is situated on the axis of the pin 41, said plate being provided with a number of teeth 44 with which a check-pawl 45 on the lever can be caused to engage.

The operation of the apparatus above described will be clear from an examination of Fig. 1, in which A indicates the position of the target at the moment of firing, A-B the direction of flight, and B the point that is hit, the distance AB indicating at the same time the distance covered by the target during the course of the time used by the projectile in reaching the target. The line of sight may be considered to be the spindle 18, which is parallel to the real line of sight passing through the hole 22 and the centre of the wire cross 25, 26, and the bore axis may be considered to be a line K passing through the centre of the sleeve 38 and being parallel to the real bore axis of the gun.

Preliminarily, supposing the target to be stationary in the air, viz at the point B (the point to be hit, which is then also the point aimed at).

Relatively to the other parts of the sight device the plate 42 is disposed and constructed in such a. manner that the lever 40, by being caused to engage the various tooth spaces (between the teeth 44) representing equidistant heights of flight, by means of the pull bar 39 displaces the carriage or sliding member 36a, 37 into such a position that the two rectangular frames 32, 33, 34 and 18, 19, which preliminarily, and corresponding to the target being stationary, are supposed to be situated in parallel vertical planes, are displaced to such an extent relatively to one another that the line of sight 18, for a certain elevation above the horizontal plane, will form with the gun axis exactly the previously calculated angle corresponding to the given elevation of line of sight and height of flight. By the subsequent adjustment of the elevation of the gun (while the lever 40 remains stationary) the sliding member 36a, 37 will be further displaced, the result being that by an increase in the elevation the angle between the gun axis and the line of sight will decrease, while by a reduction of the elevation the said angle will increaseall approximately agreeing with the adjustment of the said angle that could have been found by calculation.

In practice the procedure, as far as the operation of the heretofore considered side of the sight device is concerned, is as follows. First the height of flight is measured or estimated and-without considering the momentary position of the gun or the sight devicethe lever 40 is set into the tooth space corresponding to the height of flight con cerned and then, maybe under simultaneous required rotation sideways of the gun, the elevation of the gun is increased or decreased, until the line of sight points at the target (which preliminarily was supposed to remain stationary at the point B). The angle between the gun axis and the line of sight will then be the angle marked a. The path of the projectile is shown by a dotand-dash line marked P.

If the target, instead of being stationary at the point B (the point to be hit) is situated at A in horizontal flight towards B and with such a velocity of flight that during the course of the time used by the projectile in reaching B, the target will cover the distance A.B, then the line of sight at the moment of firing will consequently have to be directed towards A, while the direction of the gun axis has to be the same as before, since the projectile has to hit the target at the same point as before, viz at the point B. Consequently, without the direction of the gun axis being altered, the line of sight has to be turned the angle ,8 away from the above determined position.

The angle [5' is provided in the following manner: The divisions 14 along the edge of the Ion-- gitudinal slot at the top of the casing 8 indicate to a scale depending on the general dimensioning of the sight device, the various velocities of 110 flight. The scale mark vertically above the spindle 6 corresponds to the velocity zero. If the nut 11 with the universal-joint member 12 is adjusted (by gripping the head 13 and thereby turning the screw 10) to the mark corresponding to the velocity of flight of the target concerned, see Figs. 1 and 1a, and if subsequently the spindle 6 (causing the centre of the universal joint 12,17 to describe a horizontal circle C, about the said spindle) is turned into such a position that the radius 120 to the centre of the universal joint becomes parallel to the line A--B, then the line of sight will have been rotated exactly the required angle 3 about its point of intersection with the gun axis.

synchronously with the motion of the univer- 125 sal joint in the circle about the spindle 6 the wire cross 25, 26 is rotating. And the fact that the universal joint has arrived exactly at the point of the circle C, where the corresponding radius is parallel to the direction of flight A-B, is ascer- 130 tained during the sighting in that the target is then seen to move in the space between the two parallel wires 25 in the wire cross.

If the course of the target, instead of being horizontal as assumed above, forms an angle with 135 the horizontal plane (which will be an exceptional case, however), a correction for this circumstance may be introduced by adjusting, by means of the toothed segment 15 and the check-pin 16, the casing 8 to the corresponding angle with 140 the spindle 6 (see the dotted line in Fig. 1a in comparison with Fig. 6). Hereby the universal joint will be lifted slightly and, consequently, the line of sight lowered slightly relatively to the gun axis, which means that the elevation of the gun axis above the line of sight will be increased, so that the hitting point will be raised. Simultaneously with this lifting of the universal joint a rotation of the same will be effected and, thereby, a rotation of the wire cross corresponding to 150 the said angle, so that the sight device may now be operated as before, as if the target were moving in a horizontal plane.

In practice the entire operation of the sight device is not performed by several steps, as assumed for the sake of clearness in the above explanation, but simply by measuring or estimating the height of flight, the velocity of fiight and the angle between the course and a horizontal plane, after which the lever 40 is adjusted according to the height of flight and the universaljoint member 12 according to the velocity of fiight, and the casing 8 is adjusted obliquely relatively to the spindle 6 according to the angle between the course and the horizontal plane, after which the sight through the hole 22 and the centre of the wire cross is directed towards the target, and the sight is maintained there, while simultaneously the handle '7 is rotated, until the wire cross has come into such a position that the target is seen to move in the gap between the parallel wires 25 and in the direction given by the arrows 28, 29. The gun is fired at the moment when the target, during this motion, is viewed directly opposite the transverse wire 26.

In the construction shown in Figs. 8 and 9 the supporting frame is attached to a gun support, in which the machine gun is resting, and which is journaled in the supporting stand, so that the support can be swung in a vertical plane relatively to the stand, while the trunnion carrying the supporting bracket together with the plate fitted with divisions for various heights of flight and the sleeve of the supporting frame is disposed on the gun support, there being inserted as a connecting member between the supporting bracket and the stand a draw-bar, the length and manner of attachment of which are adjusted in such a manner that the supporting bracket will constantly be maintained in such a position that the spindle which is journaled therein, and serves to adjust the wire cross of the front sight member in such a manner that the double wire thereof will come into a position corresponding to the direction of flight of the air craft, will always be occupying a vertical position.

1a is the support of the machine gun which by means of trunnions 3a rests in such a manner in the supporting stand 2 that it can be swung in a vertical plane, while the supporting stand can be rotated about a vertical axis. The trunnion 3 is here attached to the side of the gun support and supports the sleeve 30, to which the rear frame member 31 of the supporting frame 31, 32, 33 and 34 is attached. 35a is a rod by means of which the front frame member 33 of the supporting frame is attached to the side of the gun support. 4 is the supporting bracket which is pivoted about the trunnion 3 and carries the plate 42 fitted with divisions. 40 is the lever, which is pivoted about the pin 41 on the plate 42, and to which the rear end of the drawbar 39 is connected, while the front end of the said bar is rotatably connected to the transverse rod 3'7 on the carriage 36, 36a, 38, which is adapted to slide back or forth on the frame members 32, 34 of the supporting frame and on the spindle 18, which forms one of the frame members of the supporting frame 18, 19 for the sight devices. 46 is an arm pivoted about the trunnion 3 and is connected to the supporting bracket 4, in such a manner that the said arm, the supporting bracket and the plate 42 as an integral unit can be swung about the trunnion. The free end of the arm 46 is connected to one end of a drawbar 47, the other end of which is connected to a pin 48 on the side of the supporting stand 2.

When according to this construction the support 1 is swung about the trunnions 3a in a vertical plane relatively to the supporting stand the entire sight device will follow along, but the supporting bracket 4 with the plate 42 will be swung about the trunnion 3 owing to the connection to the supporting stand 2 produced by means of the arm 46 and the draw-bar 47, in such a manner that the axis of the handle '7 and of the spindle 6 will always remain vertical. In consequence hereof the carriage 36, 36a, 37, 38 is displaced, by means of the draw-bar 39 in the same manner as indicated for the construction shown in Figs. 1 to 7, forward or backward on the frame members 32 and 34 of the frame 31, 32, 33, 34 and on the spindle 18 in the supporting frame for the sight devices, so that here the same adjustment of the position of the line of sight relatively to the core line will be effected as for the construction according to Figs. 1 to '7.

Having thus described my invention, what I claim is:-

1. In an anti-aircraft gun, the combination of a frame attached to the gun barrel and pivoted for movement therewith in a vertical plane, a supporting member mounted for movement in an angular path about a fixed axis disposed in the vertical plane passing through the pivotal axis of said frame, a frame having a universal connection with said supporting member and normally supported in parallel relation with said first frame, sighting devices carried by said universally supported frame, means slidable on both of said frames and connecting them in spaced relation, means for setting said slidable means thereby automatically to vary the angular relation between said frame proportionately to any variation of the inclination of the gun barrel to the horizontal, means for shifting said supporting member in a horizontal path thereby to vary the angular relation of said universally supported frame to said first frame, one of said sighting devices car-- rying direction-indicating means, and means connected with said supporting member for rotating said sighting device with relation to its supporting frame thereby to carry its direction-indicating means into parallel relation with the direction of movement of a flying target.

2. In an anti-aircraft gun, the combination of a frame attached to the gun barrel and pivoted for movement therewith in a vertical plane, a supporting member mounted for movement in an angular path about a fixedaxis disposed in the vertical plane passing through the pivotal axis of said frame, a frame having a universal connection with said supporting member and normally supported in parallel relation with said first frame, sighting devices carried by said universally supported frame, means slidable on both of said frames and connecting them in spaced relation, means for setting said slidable means thereby automatically to vary the angular relation between said frames proportionately to any variation of the inclination of the gun barrel to the horizontal, means for shifting said supporting member in a horizontal path thereby to vary the angular relation of said universally supported frame to said first frame, one of said sighting devices carrying direction-indicating means, means for moving said supporting member into inclined position with relation to the horizontal, and means operated by said movement for rotating said sighting device with relation to its supporting frame thereby to carry its direction-indicating means into parallel relation with the direction of movement of a flying target.

3. In an anti-aircraft gun mounted for pivotal movement in a vertical plane for varying its angle of inclination, the combination of a member attached to said gun for movement therewith in a plane parallel to the plane of elevational movement of the gun barrel, sighting-device supporting means mounted for movement with said gun and into and out of parallel relation to said member, means for initially adjusting said supporting means to a predetermined angular relation with said member, connecting means movably engaging said member and supporting means, and means for setting said connecting means as the gun is elevated thereby automatically to vary the angular relation of said supporting means to said member and of the line of sight and said gun proportionately to the said pivotal movement of the gun.

4. In an anti-aircraft gun mounted for pivotal movement in a vertical plane for varying its angle of inclination, the combination of a frame attached to said gun for movement therewith in a plane parallel to the plane of movement of the gun barrel, a second frame mounted for horizontal and vertical movement with said gun and also independently of said first frame, sighting devices carried by said second frame, mechanical means operative to adjust the angular relation of the second frame to the first frame in both horizontal and vertical planes, connecting means movable on both of said frames, and means for automatically setting said connecting means as the gun is elevated whereby during variation of the inclination of the gun barrel said connecting means is automatically moved to vary the angular relation of the second frame to the first frame in both horizontal and vertical planes.

WERNER CHRISTIAN LASSEN HAUBROE. 

